you have to ground the engine and the battery. some run the engine ground to the megative on the battery some don't. whatever is easier. just make sure you engine is grounded good, and the battery is ground to the chasis.
run wire from the alternator to the battery positive. run a ground from negative post on battery to chasis. then find a bolt on the engine block, and run a ground wire to either the negative terminal on the battery, or the chasis.